Approaching the sun is a perilous process, but many objects have successfully pulled off this feat. Mercury, the solar system's innermost planet, comes within 29 million miles (47 million kilometers) of the sun at its closest point, called perihelion, according to NASA. However, several known asteroids come even closer. Scott Sheppard, an astronomer at Carnegie Science, noted that asteroids with orbits crossing Mercury's, called Mercury-crossers, have highly eccentric orbits. A search through NASA's Small-Body Database shows 2024 YL3 as the current record holder, with a perihelion of 6.4 million miles (10.3 million km). Another group of celestial objects, proposed asteroids called Vulcanoids, may beat 2024 YL3. These hypothetical objects, named after the theoretical planet Vulcan, are thought to have circular orbits within Mercury's path. Numerical models suggest their orbits could be stable between 5.58 million and 23.23 million miles (8.98 million to 37.39 million km) from the sun's center, potentially bringing them closer than Mercury-crossers. However, Vulcanoids have not been observed, and a 2013 study found no evidence of their existence. Spacecraft have also come extremely close to the sun. NASA's Parker Solar Probe, launched in 2018, reached a perihelion of 4.5 million miles (7.3 million km) from the sun's center during its primary mission. The probe flew through the sun's corona, protected by a carbon foam shield. Sungrazing comets often become spectacularly bright as they approach perihelion. A 2018 study described such comets as coming closer than 1.49 million miles (2.39 million km) of the sun's center, though their precise proximity depends on orbital parameters. Man-To Hui, a researcher at the Shanghai Astronomical Observatory, noted that small sungrazers may break up due to nonuniform heating, while larger ones may be pulled apart by the sun's gravity. The Great Southern Comet of 1887 came within 446,187 miles (718,070 km) of the sun, making it the closest observed object. "Sundiving" or "sunstriking" comets, which would cross the sun's visible surface, are thought to have been more common in the early solar system. These comets would need a perihelion less than the sun's radius, or 432,244 miles (695,630 km) from the sun's center. If such a comet is ever observed, it would surpass the Great Southern Comet of 1887 as the closest object to the sun.